This application seeks shared support from NIDA and NIAAA to enable U.S. scientists to attend the 5th International Drug Abuse Research Society (IDARS) Conference to be held August 18 - 21, 2015, at the Westin Hotel in Sydney, Australia. Alcohol, psychostimulants such as methamphetamine, MDMA (Ecstasy), and other designer drugs such as GHB and bath salt, marijuana, prescription opioids, and solvents/inhalants/anesthetics are some of the most widely abused drugs in North America, Central America, South America, Europe and Asia, and their abuse has dramatically increased over the past two decades. The IDARS Conference is conceived as a scientific forum for disseminating biomedical aspects of SUD research worldwide. The main purpose is to bring basic scientists together with clinical investigators/researchers to integrate expertise and scientific findings from both domains and facilitate our understanding and study of the role of different cellular and molecular mechanisms of SUDs. The current and future research challenge is to understand which specific cellular systems undergo molecular changes to influence tolerance and dependence in motivational systems that lead to addiction and alcoholism. Therefore, this conference will cover molecular and cellular biology, biobehavioral and clinical research, and epidemiology. Particular emphasis will be given to translational research for future treatment strategies; participation by treatment researchers will be highly encouraged. Substance use disorders are global problems. Geographic separation and a lack of communication at the international level hinder the application of important research findings of vulnerability and treatment targets from one part of the world to other parts of the world. Thus, the IDARS Meeting has the specific aim to bring together basic scientists and clinical investigators from the international community to provide an in-depth understanding and current knowledge of new conceptual insights into CNS-acting drugs, drugs of abuse, and drug addiction treatments. Prior IDARS venues have included, Central America (Merida, Mexico, August 14 - 17, 2007; Mexico City, Mexico, April 15 - 19, 2013), Asia (Seoul, Republic of Korea, August 17 - 21, 2009), and the Middle East (Istanbul, Turkey, August 23 - 26, 2011). The 2015 IDARS Conference will be held August 18 - 21, at the Westin Hotel in Sydney, Australia. Abstracts of Conference proceedings will be published in the Journal of Drug and Alcohol Research.